Transformation of linear control algorithms into operationally optimal real-time tasks

Today, the role of a control algorithm is evolving from a static design, synthesised off-line to dynamic algorithms that adapt in real-time to changes in the controlled system and its environment. Hardware realisation of such control algorithms will result in complex, dynamic real-time systems. These real-time systems are expected to adapt to the time varying nature of the environment they react with. Therefore, it expected that there will be transient overloads on the processor implementing the control algorithm. In the presence of transient overloads, it may not be possible for the processor to allocate adequate computational time to each sub-task so their deadlines can be met.; This thesis focuses on transforming linear control algorithms, into anytime control algorithms that can compromise on the quality of the controller output to conserve system resources. This provides flexibility to the scheduling algorithm to guarantee on-time completion of all the real-time tasks within their respective deadlines. The thesis also presents a new model of computation, where a linear controller is transformed into a multi-rate modal system. From the point of view of real-time scheduling, this translates to the decomposition of a real-time task with given deadline to a set of sub-tasks with reduced computational overheads and varied deadlines. It is shown that implementing a controller as a multi-rate system significantly reduces the required computational resources. The decomposition of a single-rate controller to a multi-rate controller provides flexibility to the scheduling algorithm to adapt to the changes of the environment.